In Africa, the Democratic Republic of the Congo, Sudan and Somalia have the continent’s largest internally displaced populations which are among the largest in the world

LONDON (Thomson Reuters Foundation) – Counting people displaced by conflict or natural disaster is a difficult and sometimes contentious process.

The greatest number of those displaced usually falls into the category of internally displaced persons (IDPs) - citizens who are forced to flee to other parts of their home nation.

In Africa, the Democratic Republic of the Congo (DRC), Sudan and Somalia have the continent’s largest internally displaced populations which are among the largest in the world.

The U.N. Refugee Agency expects 2013 would have been “one of the worst periods for forced displacement in decades", although full figures will not be released until later this year. Mass displacements caused by recent violence in South Sudan and Central African Republic (CAR) suggest this trend may continue.

The map (see below)of five African populations displaced in recent crises shows the percentages of IDPs, as well as the most recent estimates from the U.N.’s Office for the Coordination of Humanitarian Affairs (OCHA).

A few facts about counting IDPs:

Counting IDPs is a sovereign issue. Organisations like the U.N. have no mandate to count and must ask a government’s permission. Therefore calculating numbers “is not science, it is a negotiated figure”, according to OCHA.

When access to the areas of concern is impossible, the U.N. collects lists of displaced people from other humanitarian organisations. They will remove any people counted twice and seek another source to validate the data. Only then will they agree on a figure, which becomes the reliable estimate.

Satellite tracking helps the U.N. obtain a quick overview of the situation on the ground in case of disasters or chaotic circumstances. The U.N. needs to make an assessment within a few hours while it waits for the government to ask for help.

Tracking starts immediately as a disaster happens. UNOSAT is the UN outfit with access to various countries’ satellites, which gives the agency access to maps of concentrations and movements of people.

When people are displaced from their homes they generally first seek protection with host families rather than heading directly to displacement camps. This may interfere with counting initially. Host communities will need humanitarian assistance to cope with the additional strain on public services.

The estimated 10.4 million IDPs in the 18 sub-Saharan African countries monitored in 2012 made up almost a third of the global total.

Global figures may not always illustrate the full impact of a mass displacement. For example there are some 2.7 million IDPs in the DRC, representing four percent of the population. This is around three times more than the number of IDPs in the CAR, but the CAR’s internally displaced represent roughly one fifth of its population.

The map also features:

the latest IDP estimates from OCHA and the date of the last count

the newest population figures released by the World Bank - in this case 2012